Nonspill vent plug



Dec. 29, 1942 c. F. OESTERMEYR Erm. 2,306,974

NONSPIILLA VENT PLUG vFiled March 5, 1941 42 v y//m' a 7/ )HI/ is @Wil |mili f l'v M, l. Mlm Il l4 INVENTORS l u 'N h cfzofgzimf@ F156 4 j@ #Maggy Patented Dec. 29,1942 i I NoNsrm. VENT PLUG y Carl F. Oestenneyer, Shaker Heights, and Leo E. Pucher, Cleveland, Ohio, sssignors to Willard Storage Battery Company, Cleveland, Ohio, a corporation of West Virginia Application Maren s, 1941, serial No. 381,816

c claims. p (ci. 137-139) 'I'his invention relates to so-called non-spill vent plugs which are designed to prevent the yloss of electrolyte if the battery is tilted to anymaterial extent from its normal upright position.

l Many non-spill vent plugs have been proposed? heretofore having valves which admit of .the

venting-of the cell when the battery is in upright'y or substantially upright position but which 'when' the battery is tilted a predetermined amountaregA closed by a weight which'is supported for I'OckQ- y ing movement either below or in the body of the..

vent plug.

The present non-spill vent plug is of the struction and combinations and arrangements of parts which will be described in the specification and set forth in the appended claims.

In the accompanying sheet of drawings where.. in we have shown the preferred construction and a modified form thereof.

Fig. 1 is a perspective view of the upper part of a three-cell battery, each cell of which is provided with a non-spill vent plug embodying the'v present invention;

Fig. 2 is an enlarged vertical sectional View of the vent plug in its preferred form and showing by dotted lines a portionof the cell cover to which the vent plug is applied, the section being taken substantially along the line' 2--2 of Fig. 4, the vent plug here being in upright position and the valve being open;

Fig. 3 is a similar viev,1 with the vent plug tilted and with the valve closed by the weight which is shown rocked to Valve closing position;

Fig. 4 is a transverse sectional view substantially along the line Iio Fig. 2;

Fig. 5 is a transverse sectional view substantially along the line 5-5 of Fig. 2;

Fig. 6 is a detached plan view of a baille which is employed in the upper part of the vent plug body of Figs. 1 to 5; and

Fig. '1 is a view similar to Fig. 2 but showing a modification. Y'

Referring now to the drawing, we have shown in Fig.- 1 a three-cen battery but the number of cells is of course immaterial to the invention since each cell is provided with a vent plug embodying weer wherein a valve actuating weight is mounted fofr" AsiSC ized as consisting in certain novel-details of coning I4 (see Fig. 2) internally threaded to receive the vent plug.

vThe vent plug includes a hollow cylindrical body 'I5 having at the bottom'areduced neck portion I6 which isy externally @threaded so that it ',may be screwed into the threaded opening Il. At the junction of the bodyportion I5 and the reduced portion I8 a. shoulder I1 is provided which is adapted to engage a soft sealing gasket I8 resting on the upper flange of the cover. If desired, the lower side of the shoulder I1 may be provided witha series of small annular ribs or flutes I9 to facilitate the sealing action when the vent plug is screwed to its normal position. l

At the bottom of the neck portion I8 of the vent plug body is a ledge 20 which defines an annular valve opening 2I,- the ledge' having a flat lower face 22 constituting a valve seat and having a sloping upper face 23 which inclines downwardly and inwardly to the valve opening 2|.

The top of the vent plug body I 5 is closed by a cap 24 which in this instance has a notched peripheral flange resting on the top edge of the body I5, the ange fitting into the top portion of the body. The cap may be secured in place in any suitable manner, as by being cemented in place, or, if desired, by being screw-threaded in place as in the form of the invention shown in Fig. 7. The cap 24 has a vent opening 25 which extends through a central protuberance 26 formed on the underside of the cap and extending down a suitable distance into the upper part of the chamber formed by the body I5.

Inside the barrel or body I5 o f the vent plug is a weight 21 which is formed of a suitable heavy material inert to battery electrolyte, such as lead. This weight is substantially frusto-,conical in shape with its relatively large end at the bottom, this end being slightly smaller in diameter than the internal diameter of the Vent plug body I5. Attched to the bottom of the Weight 2l is a disk 28 which rests upon an internal shoulder 29 of the vent plug body I5 just above the reduced neck I6 thereof. The inner wall or surface of the reduced neck I6 from the shoulder 29 t0 the upper sloping wall 23 of the ledge 20 is shaped so as to facilitate the downward flow of any electrolyte which may by chance have passed the valve or which may have passed upwardly from the cell with the evolved gases. lPreferably this wall, at least adjacent the shoulder 29, is curved downwardly and inwardly substantially as shown in Figs. 2 and 3. The disk 28, the vent plug body I5, the cap 24, and the baiiie' which is between the l upper end of the weight and the cap 24 and is to be referred to presently will be formed of suitable plastic or plastics inert to battery electrolyte. We prefer to employ the plastic known as polystyrene although any other suitable plastic or combination of plastics may be employed.

The disk 28 forms the base for the weight 2l and is capable of rocking or tilting in any direction on the ledge 23. Its diameter is somewhat smaller than the internal diameter of the body I5, and the upper and lower edges of the disk are rounded as shown at 28a so as to facilitate the rocking action and also to prevent any tendency to bind or stick in the corner of the ledge or against the inner annular wall of the vent plug body.

The weight and the disk may be secured together in any suitable manner but preferably by providing on the bottom of the weight a series of equally spaced lugs 30 which t into similarly spaced openings 3| formed in the disk 28. In this instance, as shown in -Figs. 2 and 3, the openings are ared downwardly and outwardly and the lugs are spread 'so as to lock the disk and the weight together. f course the lugs and the openings may b e straight and these parts may be locked together by peening over the lower ends of the lugs. three sets of lugs and openings 3| are employed. Between the openings 3| the disk is provided with a plurality of openings 32 and the lower end of the weight is provided with diago'nally disposed openings 33 their lower ends being in alignment with the openings 32 and their upper ends at the lower peripheral surface of the weight. Three sets ot' these openings are preferably employed as indicated in Fig. 4 although the number may be changed as desired. These openings 32 and 33 are for the purpose oi permitting the upward passage of gas produced in the cell and the return of any electrolyte which may get by the valve at the lower end of the vent plug.

'I'he tilting of the weight is adapted to actuate the valve which includes a stem 34 provided at its upper end-With a head 35 having a freely moving ball and socket connection with the plastic base 28 of the weight. 'I'he head has a spherical surface which engages a spherical surface formed in the wall of an opening in the base 28 through which the head partially extends and in which it is seated. The upper part of the head projectsinto a cavity 36 formed in the lower part 'of the weight and the upper part of the head has a. rounded portion which is close to but out of contact with the top wall of the cavity 36.

The stem extends downwardly from the weight and disk 28 through the valve opening 2| formed in the ledge 20 and the portion which extends through the valve opening is ribbed or fluted as shown at 31 so that it will have a guiding action in the opening and maintain the stem 34 substantially axially of the vent plug at all times. We nd that three flutes or guide ribs are preferable as that number affords the proper guiding action, and, furthermore, we iind that three ribs provide the most efficient construction for securing the return of any electrolyte which may have accidentally passed the valve at the lower end of the stem. If more ilutes yor guide ribs are used,

the electrolyte seems to cling to the valve stem and even to rise apparently by capillary action. For the same reason it is desirable that the inner wall of the reduced portion I6 of the vent plug body |5 be curved fora substantial part of its length for otherwise the acid is not effectively returned to the cell.

' At.the bottom of the stem 34 beneath the ribbed portion 31 is a bottom enlargement 38 and between this and the ribs is a neck portion which is surrounded by a movable valve member in the As shown by dotted lines in Fig. 4,

rubber or equivalent soft plastic material. .The diameter of the disk is of course somewhat greater than the diameter of the valve opening 2|, and when the weight is tilted to a predetermined position, the bottom enlargement 38 of the valve stem pulls the disk up against the lower surface or seat 22 of the ledge 28 so as to close and seal the valve opening against the passage of electrolyte therefrom. It is quite important that' a highly efllcient valve seating action be obtained, i. e., that the valve member 33 firmly engage the valve seat 22 with substantially the same pressure all around. 'I'his result is obtained by providing at the lower end of the neck portion where it joins the lower enlargement 38 an annular iillet 40. When the soft valve member or washer 33 is placed around the neck portion of the valve stem between the enlargement 38 and the ribs 31, the fillet 40 prevents the washer from seating ilush with the top surface of the enlargement 33, but when the valve stem is lifted due to the tilting of the weight 21, the valve member 33 is forced against the valve seat 22 not only by the pressure exerted by the enlargement 38 as the valve stem 34 is moved upwardly, but also by the tension or stress set up in the soft valve member 33 by the llet 40. By using a soft rubber valve member or washer 33 and the fillet 40, a uniform sealing action al1 around the valve seat 22 is obtained notwithstanding the fact that when the weight is tilted and the valve stem moves up the pressure or pulling action may not be exactly centered with respect to the axis of the valve. The bottom enlargement 38 is slightly smaller in diameter than the valve opening 2|. This aids the fillet in securing a good valve seating action, for there is a tendency for the bottom Y member to push the soft rubber washer or ,valve wall of the cavity 36 so that upon the return of the weight to substantially its normal position the wall forming the top 0f the cavity 38 will strike the top of the head 35 and force the stem down to its proper positionshown in Fig. 2. We might state further that the valve member may stick to the valve seat or gas pressure built up in the cell when the valve is closed may act form of a disk 33 which may be formed of soft lb to hold the valve in closed position. Thus there is a pressure or perhaps a stickiness that must be overcome and that necessitates a blow on the top of the valve stem rather than a mere push. It should also be noted that when the valve is closed the bottom edges of the ribs 31 are out of contact with the soft rubber valve member. When the valve stem is struck by the weight in returning to its normalupright position, the ribs move against the rubber valve member with something of a blow andthus break the valve seal. In other words, we are not simply relying on the adhesion of the rubber valve member against the valve stem to transmit the moving force in the valve stem to the rubber member but we use the action of the ribs 31 in striking against the valve member.

' asoae'r'a two openings 43 and 44, one preferably located at the lower part of the inclined baille and one at the top, as indicated-.in Figs. 2 and 6. In the event any electrolyte passes through the valve opening 2l, it may pass through the openings 32 and 33 and then through one or both of the openings 43 and 44 of the baffle particularly if the battery is substantially or wholly inverted in which case the electrolyte collects in the pocket on the underside of the cap 24 around the pro'- tuberance 25. When the battery is righted, the

electrolyte will return through the lower opening 4I and possibly a portion through the higher opening 44, but, in any event, the opening 44 is sulciently free to take care of and to permit the venting of any collected gas. This construction prevents the surging of any gas through the vent opening 25 at the time that the electrolyte is returning and thus avoids the likelihood of electrolyte being carried out through the top of the vent plug.

The degree of tilting of the battery to cause the weight 21 to rock in the vent plug and bring about the closing of the valve at the lower end of the vent plug will depend upon the height of the weight of the weight the'sooner the weight will rock to a position to close the valve as the battery is tilted from normal upright position. This may be termed the critical angle and may be varied as desired. It is generally preferable, however, that this angle of battery tilt be not less than 20 and in most instances it will be sufficient ii the'weight rocks in the vent plug and the valve closes when the battery has been tilted approximately to 35 from normal position. With the construction illustrated, the valve will close when the battery is tilted approximately 30 from normal.

It is desirable that the construction be such that the surface of the weight at no time contact the inner cylindrical wall of the vent plug body, and that result is accomplished with the construction illustrated. It will be obvious also that the proper closing of the valye at the lower end of the vent plug will occur regardless of the direction in which the weight is tilted.

The modified construction illustrated in Fig. 'I operates on the principle of the vent plug first described and therefore only a brief description of the modification will be necessary.

The vent plug of Fig. '7 is provided with a body 45 closed at the top by a cap 46 in this instance screwed into the top of the body 45 and provided with a vent opening 41 extending down through an inwardly projecting protuberance. Beneath the cap is a baille 48 which rests upon an internal shoulder of the vent plug body and may be secured in place in any suitable manner as by cementing. The main portion of the baille is in the form of an inverted cone with an opening 49 at the bottom and with one or more openings 55 in the conical wall and somewhat above the opening 49. Generally one opening 50 will be suflicent. The body 45 has at the bottom a reduced portion 45a which is externally threaded and is adapted to be screwed into the flanged opening in the cover. At the bottom of the reduced portion is a ledge 45b having a valve opening 45 21. The higher the center of gravity Aly-shaped head 58 of therein, the lower surface of the ledge forming a valve seat as before.

In the vent plug body is a weight 5| of lead or equivalent material which will be shaped so that it will not engage the inner-wall of the vent plug body when the battery is tilted any amount in any direction. The weight has at the bottom an annular reduced portion 52 having a groove 53 next to the ilat'bottom of the weight and it is supported by a plastic base 54 with a disk-like lower portion 55 which rests upon an internal shoulder 5S formed at the top' of the reduced portion Aa of the vent plug body and provided with a rounded margin so as to facilitate the smooth rocking of the weight in any direction. The disk-like lower portion 55 of the base has a number of openings such as shown at 55a to permitl venting and the return of electrolyte. The base 54 has a central upstanding tubular portion 51 which is secured to the reduced portion 52 of the weight, the latter extending into the top of the tubular portion 51 which has a bead projecting into and lling the groove 53. The weight.

and the plasticbase may be assembled or fitted together whenthe base is hot and somewhat pliable and extensible, and after these parts are assembled the top of the pliable base 51 is pinched inward while it is still in a heated state so as to grip the reduced portion or lower extension of the weight.

The lower part of the cavity formed in the base 54 is spherical in shape and receives a sphericalthe valve stem 59 which extends down through the valve opening 45C, the portion of the stem passing through the opening having guide ribs 6I as before, Supported on the stern between the guide ribs 6I and the bottom enlargement 62 of the stem beneath the ledge 45b is a valve member 63 which, as before, is formed of soft` rubber or equivalent4 plastic material. It might lbe here stated that the valve plug body 45, the cap 4B, the baille 48, and the base 54 of the weight will be formed of suitable plastic or plastics, such as polystyrene, hard rubber, or the like. If necessary, the enlargement 58 may be fitted into the spherically shaped cavity of the base 54 when the latter is in a heated and extensible condition.

With this modified form of vent plug, like with the form first described, when the battery is tilted through a predetermined angle from normal position (which may be varied by varying the height of the center of4 gravity of the weight) the weight 5i and the plastic base 51 will rock on the shoulder 5B and thus pull up the valve stem and cause the soft Valve member 53 to close and seal the valve opening 45 at the lower end of the vent plug.v When the ,battery tilts back, as soon as the vertical line passing through the center of gravity of the weight again passes through the bottom flange 55 of the plastic base, the weight will rock back to its normal position, again unseating the valve member 63.

Preferably the clearance between the upper end of the stem enlargement 58 and the bottom of the lower extension 52 of the weight is such thatif, when theweight returns to normal position, the valve member 63 tends to stick against the valve seat, the lower end 52 of the weight will strike the to'p of the enlargement 58 of the stem and positively move the stem to its lower normal position shown in Fig, 7.

Also, if desired, the distance between the ribbed portion 6I and the lower enlargement 62 of the thickness of the valve member 63, and the neck portion of the stem which is surrounded 'by the valve member il may have a illlet as in the construction ilrst described so as to insure a tight and even sealing action between the valve seat and the valve member all around the latter.

While we have shown the preferred construction and a modied construction, we do not desire to be conned tothe precise details illustrated and described but aim in our claims to cover all modifications which do not involve a departure from the spirit and the scope of the invention.

Having thus described our invention, we claim:

l. A non-spill vent plug comprising a hollow body having a vent orifice at the top and provided with a reduced lower end adapted to be iltted into an opening of a battery cell cover and provided at the bottom thereof with an inwardly extending ledge dening an annular valve opening, the lower side of the ledge forming a valve seat, said vent plug body having an inter.

nal shoulder above the reduced portion, a weight in the body having an annular base engaging and adapted to rock on said internal shoulder, a valve stem having a ball and socket connection with the base of the weight and extending downwardly` therefrom, said stem having a fluted or ribbed guide portion extending through the valve opening and having an enlargement below the latter, and a substantially dat valve member between said guide portion and the lower enlargement of the stem and adapted to be drawn up against said valve seat when the weight is rocked due to tilting of the vent plug.

2. A non-spill vent plug provided with a hollow bcdy having a vent opening at the top and having a reduced lower end adapted to be fitted into an opening of a battery cell cover, said reduced portion having a ledge atthe bottom with a valve opening formed therein, an internal shoulder adiacent the top oi said reduced portion, a weight in said body, a stem having universal connection with the bottom of the weight, the weight having at the bottom a chambered portion receiving the upper end of the stem, the stem extending downwardly through and below said valve opening and provided with a shoulder at its lower end, and a washer-like soft valve member surrounding said stem above the shoulder, the construction being such that when the vent plug is tilted a predetermined amount from normal upright position the weight will be rocked on saidinternal shoulder of the bodyV pulling the stem upward and causing the valve member to engage the lower face of said ledge around said opening, the stem having immediately above said shoulder at its lower end a illlet adapted to be drawn up into the bore of the valve member and to press into and stress the valve member when the latter is moved by the stem to valve closing position.

3. A non-spill vent plug comprising a. hollow body havinga top with a vent opening and provided at the bottom with a reduced portion adapted to be fitted into the opening of a battery cell cover, said reduced portion having at the bottom an inwardly extending ledge with a valve opening, the 'body having an internal shoulder above said reduced portion, a weight in said body having a base in the form of a separate member formed from a non-metallic material and secured to the lower end of the weight, and a valve stem having a connection with said base adapted to permit universal relative movement between said base and stem, said base having an aperture through which the stem extends and having an enlarged head abofe theaperture, the stem extending down through the aperture of said base and through the valve opening and having adjacent its lower end a valve adapted to be drawn upwardly against the lower side oi' said ledge by the rocking of the weight so as to close said valve opening.

4. A non-spill vent plug comprising a hollow body having a vent orlilce at the top and provided with a reduced lower end adapted to be fitted into an opening of a battery cell cover and provided at the bottom thereof with an inwardly extending ledge defining an annular valve opening, the lower side of the ledge forming a valve seat, said vent plug body having an internal shoulder above the reduced portion, a weight in the body having an annular base engaging and adapted to rock on said internal shoulder, a valve stem having a ball and socket connection with the base of the weight vand extending downwardly therefrom, said stem having a iluted or ribbed guide p ortion extending through the valve opening and having an enlargement below the latter, a substantially nat valve member between said guide portion and the lower enlargement oi.' the stem and adapted to be drawn up against said valve seat when the weight is rocked due to tilting of the vent plug, and a perforated baille between the weight and the top of the vent plug body.

5. A non-spill vent plug comprising a hollow body having a vent orice at the top and provided with a reduced lower end adapted to be ntted into an opening of a battery cell cover and provided at the bottom thereof with an inwardly extending ledge defining an annular valve` opening, the lower side of ,the ledge forming a valve seat, said vent plug body having an internal shoulder above the reduced portion, a weight in the body having an annular base engaging and adapted to rock on said internal shoulder, a valve stem having a ball and socket connection with the base of the weight and extending downwardly therefrom, said stem having a iluted or ribbed guide portion extending through the valve opening and having an enlargement below the latter, and a substantially flat valve member between said guide portion and the lower enlargement of the stem and adapted to be drawn up against said valve seat when the weightis rocked due to tilting of the vent plug, the base ofthe weight having one or more openings for normal venting purposes and for the return of the electrolyte.

6. A non-spill vent plug comprising a hollow body having a vent oriilce at the top and adapted to be tted into the opening of a battery cell cover, said body having near its lower end an internal shoulder and at its lower end al valve opening, a'weight in the body formed from metallic material inert to the battery electrolyte, said weight having secured to its lower end a base member formed from a plastic inert to the battery electrolyte, the marginal portion of said plastic base engaging and adapted to rock on said internal shoulder of the body, and a valve provided with a stem having a ball and socket connection with the plastic base of the weight and provided at its lower end with a valve member adapted to close said valve opening when the stem is drawn upwardly as said weight is rocked when the vent plug is tilted a predetermined amount from its normal upright position.

CARL F. OES'I'ERMEYER. LEO E. PUCHER. 

